"It definitely looks like a young Al Horford -- All-Star Al Horford, to be honest," said Brown, who couldn't even drive a car when Horford earned consecutive All-Star nods back in 2010 and 2011. "He's playing really well at a high level. If he keeps it up, we're gonna be really tough."

Horford, back in Boston's starting lineup Sunday after missing the previous two games due to a concussion, scored a team-high 21 points on an efficient 8-of-9 shooting. And it was both Horford and Brown who paired up to force DeMar DeRozan into two tough shots in the final seconds as Boston escaped with a 95-94 triumph at TD Garden.

Told of Brown's comments, Horford laughed at the suggestion.

"I don't know if young Al Horford played like this, to be honest," said Horford. "It's been years of working on my game and trying to play this new way. This is the style the NBA is shifting towards, and it's taken me a couple years to get comfortable and play like this, so the young Al Horford can shoot 3s."

Horford, mind you, is 31 years old and yet he's still the elder statesman in Boston's locker room. And many of his (much) younger teammates enjoyed the notion of how Grandpa Al is turning back the clock.

"Al's getting to the basket. He's dunking on guys. He's not grabbing his knees," joked Marcus Smart. "Definitely, Al's playing young again. That's a cool way to put it."

It's been 26 days since the Celtics last lost a game, and, despite a rash of injuries and a fledgling roster, their winning streak continued Sunday.

To put the length of Boston's winning streak in perspective, the last time the Celtics lost, it was 30 degrees warmer in Boston. Since dropping their home opener to the Milwaukee Bucks on Oct. 18, one night after Boston lost Gordon Hayward to a season-ending ankle injury in Cleveland, the Celtics have utilized six different starting lineups and six different rookies and found different ways to win each night.

On Sunday, the Celtics were without Kyrie Irving (facial fracture) but got back Horford to steady a young team in a key game against a chief Eastern Conference rival. Horford, outstanding at both ends of the court this season, picked up right where he left off.

Now all that stands between Boston and a 13-game winning streak heading into Thursday's visit from the Golden State Warriors is a Tuesday night trip to Brooklyn.

AP Photo/Winslow Townson

The Raptors had two chances to win Sunday's game, but DeMar DeRozan missed a pair of pull-up jumpers -- the first defended by Horford, the other by Brown. An offensive foul on rookie Jayson Tatum gave the Raptors a second gasp, but Boston's league-leading defense rose to the challenge again. Horford is a big reason why the Celtics top the NBA in defensive rating this season.

The Celtics labored through an abysmal first half, shooting 33 percent from the floor. A four-point play by Terry Rozier in the final seconds of the second quarter was 20 percent of their output in the frame. An offensive explosion followed in the third quarter, and when Horford and Brown hit back-to-back 3s, Celtics co-owner Wyc Grousbeck from his baseline seat implored fans to get loud.

But nothing has come particularly easy for Boston on this winning streak, and this game would be no different. DeRozan and Kyle Lowry paired up for 43 points on 13-of-32 shooting.

The Celtics countered with a balanced output with five different players in double figures, including 16 points from Rozier off the bench. Brown added 18, and Smart had 14 points while being a defensive pest.

Irving, two days after getting inadvertently elbowed in the face by teammate Aron Baynes, was not at TD Garden for Sunday's game. He was meeting with a specialist to examine the fracture beneath his right eye and get fitted for the protective mask he'll wear when he returns to game action.

Stevens didn't know whether that return will occur Tuesday night when the Celtics travel to Brooklyn but said that, with Irving pained only by the facial fracture and thus free of concussion symptoms, the team is hopeful he'll be on the court "sooner rather than later."